Process for the preparation of mercaptans



Patented June 7, 1949' e umrao srA'ras 4 PATENT orrica 2.412.410

raocnss so 'rr a r a a r aaArioR or Lawrence '1. Elly. Roselle, N. 1., auignor to Standon! Oil Development Company, a corporation of Delaware No Drawing. Application August 4, 1945, Serial No. 809,040

10 Claims. (Cl. 280-809) This invention relates to a method of prepartrample! ing mercaptans by the reaction oi hydrogen sul e the or a shamans:

e a ype ca s duso hydro cm It is an this mventmn pmvlde the 5 f2: 0! gm st z nic 611101 126 con t si ed i art with an improved method of reacting an ora 200 fl k m mm m made at room 8mm halide with hydmgen sulfide by catalyzing temperature and an excess of hydrogen sulfide the reaction with a Friedel-Crafts type catalyst. was added There w no n for d on It is another object of this invention to catalyze addition of the hydrogen mam the addb the reaction between an organic halide and hy- 10 mm of hydrogen sulfide was stopped (mute droeen sulfide with e chemical agent which acts dium carbonate solution in slight excess oi. that according to what is known in the art as a true required neutralize the hydrogen chloride i yst; formed b the reaction was added and a reel 1- It is another and further object or this inventate was g m Sodium carbonate f fl tion tolpriaparteh rgercaptans by an efiicient and used was made by ding cm 0,35% aqueous econom ca me o sodium carbonate to 1043 cc. of water. The hi- These and other objects appea m e clearly drogen sulfide was bubbled into the above solufrom the detailed description and claims which on t male of 5 10- o, per second for 1 /2 follow. hours; there is only a we I slight evolution of Heretofore, mercaptans have been made from 20 hydrogen chloride at the 2nd 0! the 1 /2 hour the reaction of an or an c halide wit hyd e period. The neutralized reaction mixture was s lfi y the use of analkaline reagent. This steam-distllledto obtain tertiary octyl mercaptan. alkaline reagent acted to form a hydrogen sulfide Example 2 salt which, in turn, reacted with the organic halide; it was therefore necessary to use stoichio- 26 Hydrogen sulfide at he r f /2 '1 D r metric quantities of caustic in order to complete 0nd W1!s bubbled a Period One hour mm a the reaction. The alkaline reagent did not act as mixture of 9237 grams of tertiary butyl chloride a true catalyst There has been a large and 3 cc. of anhydrous stannic chloride contained sumption of caustic in the production or merso in a one liter flask equipped with a stirrer and captans as made by the methods practiced herea reflux condenser- The reaction mixture was totem stirred throughout the addition of the hydrogen 7 It has now been discovered that mercaptans sulfide and stirring was continued for 15 minutes can be prepared by reacting an organic halide after the hydrogen sulfide addition was comwithh dro en sulfideinthe resenceoiacatal st pleted- 200 mute aqueous sodium select; i the class kgown in the art 36 bonate was added with stirring to the reaction priedehcmfts type catalyst, such as boron mixture, followed by a steam distillation of the fluoride hydrogen flu id stanmc chloride, solution. Tertiary butyi mercaptan was obaluminum chloride, titanium chloride, ferric tamed m the dismlatechloride, etc. These Friedei-Crafts type catalysts Example 3 behave in the reaction between organic halides and hydrogen sulfide as true catalysts. A mixture f y o n Suifldeand boron tri- The following equation probably represents the fluoride containing 1% of the letter was passed reaction taking place between an organic halide into 149 grams 0f W h10ride and hydrogen sulfide: tained in a one liter flask equipped with a stirrer and a refiux container over a period of 1 hours. Friedel-Craits type catalyst This constitutes an excess of hydrogen sulfide. RX+HS Rs x Vigorous stirring was employed during the addi tion of the gaseous mixture and stirring was con- In the above equation R represents an organic tinued for 15 minutes after addition of gases was group such as alkyl, aryl, alkaryl and aralkyl; 0 ended. The reaction mixture was washed with Xrepresents ahalogen atom. water and neutralized with aqueous sodium bi- The following examples illustrate some applicarbonate and then dried over anhydrous potascations of the invention but it is not intended slum carbonate, The organic material was i'racthat the invention be restricted by or to the tionally distilled to obtain tertiary butyl examples. e merca'ptan. Y

Thetemperature at which the reaction is made upon the catalyst chosen and may vary widely,

but the ordinary practice is to make the reaction at room temperature.

A large number of organic halides not included in the examples'set out, above may be employed in this invention. The organic halides may be of the alkyl, aryl, alkaryl and aralkyl types and the alkyl and aralkyl types ma be primary, secondary or tertiary in nature.'--- Other substituents may be present in the organic halides provided they are not affected by the catalyst. Such things as are afiected by thelc atalyst' would include esters and ketones.

Some examples of organic halides which may .be employed in this invention-are listed-below, but the scope of the invention is not intended to be limited thereby:

Benzyl chloride Parachlbrbenzyl chloride Bromohenzene Iodobenzene V Tertiary'butyl chloride Isopropyl chloride Butyl chloride Octyl chloride Amyl chloride Dodecyl bromide Dodecyl chloride In the preferred form of the invention primary, secondary and tertiary" alkyl halides are employed to obtain-the corresponding mercaptans.

The mercaptans' have a variety of uses, among which are their uses -as promoters and modifiers in emulsion polymerization for the preparation of synthetic rubbers. The mercaptans have a wide and recognized valuein'the art for the making of a variety of derivatives through the reaction of various organic and inorganic substances with the reactiveSH group in 'the mercaptan molecule.

The mercaptans described can be made according to the invention by a continuous process by mixing a gaseous catalyst such as BF: or HF with the H28 and contacting the mixture of gases with the halide. The'm'ercaptan as it is formed is continuously removed. When a solid catalyst depends upon the organic halide used as well as What is claimed is:

1. A process for making mercaptans which comprises reacting a tertiary alkyl halide with hydrogen sulfide at room temperature in the presence of a Friedel-Crafts type catalyst.

2. A process for making tertiary butyl mercaptan which comprises reacting tertiary butyl chloride with hydrogen sulfide at room temperature in the presence of'a Friedel-Craits type catalyst.

3. A process for making diisobutyl mercaptane which comprises reacting tertiary octyl chloride with hydrogen sulfide at room temperature in the presence of a Friedel-Crafts type catalyst.

4. A process of making mercaptans having the general formula, RSH, wherein R represents a hydrocarbon group containing an alkyl radical which comprises reacting hydrogen sulfide at room temperature in the presence of a Friedei- Crafts type catalyst with an organic halide of the formula, RiX, where R1 represents an alkyl radical and X represents a halogen atom.

5. Process according to claim 4 in which the Friedel-Crafts type catalyst is boron fluoride.

6. Process according to claim 4 in which the Friedel-Crafts type, catalyst is hydrogen fluoride.

7. Process according to claim 4 in which the Friedel-Crafts type catalyst is tin tetrachloride.

8. Process according to claim 4 in which a primary carbon atom in the hydrocarbon R1 group of the organic halide is bonded to the halogen atom.

9. Process according to claim 4 in which a tertiary carbon atom in the hydrocarbon R1 group of the organic halide is bonded to the halogen atom.

10. Process for making a mei'captan which comprise reacting hydrogen sulfide with an alkyl chloride at room temperature in the presence of a Friedel-Crafts type catalyst.

LAWRENCE T. EBY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Ai'ndt Berichte," vol. 63, pages 2390-2393. 

